The Australian Transport Safety Bureau (ATSB) is Australia's national transport safety investigator. The ATSB's function is to improve safety and public confidence in the aviation, marine and rail modes of transport. The ATSB is Australia's prime agency for the independent investigation of civil aviation, rail and maritime accidents, incidents and safety deficiencies.

Aviation safety issues and actions

Interim Recommendation issued to: Boeing Co

Output text

The Bureau of Air Safety Investigation recommends that Boeing
Commercial Airplane Group alert Boeing 737 operators to this safety
deficiency and implement an appropriate inspection program.

As a result of investigation into this occurrence, the Bureau
simultaneously issues the following interim recommendations:

IR990020

The Bureau of Air Safety Investigation recommends that Boeing
Commercial Airplane Group review the effectiveness of Service
Bulletin 737-32A1224.

IR990021

The Bureau of Air Safety Investigation recommends that the Federal
Aviation Administration note the above safety deficiency and
interim recommendations and take appropriate action as considered
necessary to ensure the integrity of Boeing 737 main landing gear
actuator beam arm assemblies.

IR990022

The Bureau of Air Safety Investigation recommends that the Civil
Aviation Safety Authority initiate appropriate action to ensure
that Australian operators of Boeing 737 aircraft immediately
inspect all main landing gear actuator beam arm assemblies for
evidence of cracking.

IR990023

The Bureau of Air Safety Investigation recommends that Australian
operators of Boeing 737 note the above safety deficiency and
interim recommendations and take appropriate action as considered
necessary to ensure the integrity of Boeing 737 main landing gear
actuator beam arm assemblies.

Initial response

Initial response

Date issued:

06 April 1999

Response from:

Boeing Co

Action status:

Closed - Accepted

Response text:

Recommendation IR990019 says that BCAG should alert 737
operators to the safety deficiency and implement an appropriate
inspection program. In response to this, we have released Boeing
All- Operator Message M-7200-99-02383 dated 26 March 1999; a copy
of this is enclosed for your reference (see enclosure 2). In
summary we plan to release an alert service bulletin (737-32A1314)
by the end of April, 1999. This bulletin will call for the
resumption of the ultrasonic inspections of all Main Landing Gear
Beam Arms every 600 flight cycles upon the accumulation of 10,000
cycles or 4 years (whichever comes first). This will be considered
interim action until we have analyzed and implemented the course of
terminating action to preclude the onset of corrosion noted in the
parts.